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justdream
2009-05-14, 08:18 PM
Experts,
In the attached image, we could see that the user is connected to sector 0, while at the same time it detected better signal strength from sector 1,
What does it mean? Sorry for disturbing you by my questions but I just want to learn and understand in more details

gprastomo
2009-05-14, 08:34 PM
Hi my friend,

It doesnt mean the better signal always serve the ue, for the 2G network dualband, we have cell reselection for idle and handover for connected mode, each has different triggering condition to change the server.
For Idle mode you can see C2, ue always select the better C2.
For connected mode, you should verify whether the ho triggering condition have been met or not yet, ie handover margin or ho due to DL/UL qual/level, if it is not yet met so ho will not taking place

br

ghassen
2009-05-14, 08:49 PM
Experts,
In the attached image, we could see that the user is connected to sector 0, while at the same time it detected better signal strength from sector 1,
What does it mean? Sorry for disturbing you by my questions but I just want to learn and understand in more details

you can have a better signal level and a worst signal quality and the the mobile will connect to a balanced creterion between quality and level

justdream
2009-05-14, 08:59 PM
Thanks a lot Gito,
could you give us more information about ho triggering conditions???

ghassen
2009-05-14, 09:01 PM
Thanks a lot Gito,
could you give us more information about ho triggering conditions???

for trigering event i have posted this explanantion about cell selection and reselection
http://www.finetopix.com/showthread.php?t=3359

gprastomo
2009-05-15, 07:35 PM
Hi my friend,

Usually there are some types of HO triggering conditions (usually depends on vendor implementation) for GSM :
1. UL/DL RxLevel
2. UL/DL Quality
3. Power Budget
4. Fast Uplink
5. Traffic Handover
etc

br


Thanks a lot Gito,
could you give us more information about ho triggering conditions???

maverrickforever
2009-08-16, 02:51 AM
dear gprastomo, i have a question for u. U said that there are parameters for handover, is there something which can help me reduce call drops in fast moving vehicles like train.

eyaOpti_guy
2009-08-16, 03:28 AM
Connected mode:
1. This is a very normal situation if you are using a channel with power control enabled, the power you are measuring on the serving cell is actually a reduced power due to power control, while the power measured on the neighboring cells is measured on the BCCH which will never be a subject to power control, so when your handover algorithm compensates your current channel measurements by adding the reductions caused by power control it detects that this connection is still within the cell boarder and thus no handover will be triggered.
PS: the level shown as serving cell BCCH level is actually the level of the current TCH you are using, and there is no way to measure the serving cell BCCH level unless you are using an optional feature "Own BCCH Measurement"..
2. High Handover margins may be applied to all these relations, which is unlikely to be the situation.
Idle mode: negative CRO may be applied to all the adjacent cells all the time "unlikely the case", or a positive CRO is applied to the current cell after a certain time..
PS: Idle mode behavior can be clearly monitored for offsets settings by means if rxlev and C2 values..

Experts,
In the attached image, we could see that the user is connected to sector 0, while at the same time it detected better signal strength from sector 1,
What does it mean? Sorry for disturbing you by my questions but I just want to learn and understand in more details

guess.who
2009-08-16, 06:52 PM
thats a really good answer by evas...